Lifting and excavating apparatus

ABSTRACT

An improved construction for a backhoe which has a supporting member, a boom having a longitudinal axis and being pivotally connected at one end to the supporting member and arranged to be rotated at that end about a first horizontal axis and swung at that end about a vertical axis, a dipper stick pivotally connected to the boom, arranged to be rotated with respect to the boom about a second horizontal axis and arranged to have connected thereto, at the end remote from the second horizontal axis and the boom, elements, respectively for excavating and lifting. According to the improvement the boom and the dipper stick are pivotally connected to each other at their adjacent ends and the backhoe includes a mechanism connected both to the boom and the dipper stick for rotating the dipper stick about the second horizontal axis on either side of the longitudinal axis of the boom.

United States Patent Arnold 51 May 30, 1972 [54] LIFTING AND EXCAVATING APPARATUS Carroll H. Arnold, Westminster, Mass.

[73] Assignee: Wain-Roy, Hubbardston, Mass.

22 Filed: on. 15, 1970 [21] Appl. No.: 81,002

[72] Inventor:

FOREIGN PATENTS OR APPLICATIONS 1,395,675 3/1964 France ..214/138 Primary Examiner-Philip Arnold Att0meyW. R. Hulbert 5 7] ABSTRACT An improved construction for a backhoe which has a supporting member, a boom having a longitudinal axis and being pivotally connected at one end to the supporting member and arranged to be rotated at that end about a first horizontal axis and swung at that end about a vertical axis, a dipper stick pivotally connected to the boom, arranged to be rotated with respect to the boom about a second horizontal axis and arranged to have connected thereto, at the end remote from the second horizontal axis and the boom, elements, respectively for excavating and lifting. According to the improvement the boom and the dipper stick are pivotally connected to each other at their adjacent ends and the backhoe includes a mechanism connected both to the boom and the dipper stick for rotating the dipper stick about the second horizontal axis on either side of the longitudinal axis of the boom.

7 Claims, 6 Drawing Figures PATENTEUHAY 30 I972 SHEET 10? 2 FIG I PATENTEDmmao I972 3,666,124

SHEET 2 0r 2 22 26 24 I6 l//// f/7//// LIFTING AND EXCAVATING APPARATUS This invention relates to lifting and excavating apparatus and in particular to a new and improved hydraulic backhoe attachment for a vehicle.

Objects of the invention are to provide such a backhoe attachment which has a shorter transport length and lower transport height than is provided by conventional backhoes, has a center of gravity in transit which is substantially closer to the vehicle rear axle, permits larger backhoes to be installed on four-wheel drive and track-type vehicles, permits swinging of a dipper stick through a full 360, may effectively be employed as a side boom, requires a relatively low lifting force, provides maximum crowd moment at any digging depth, minimizes the effects of cylinder leakage during lifting operations and transport, and permits excavation under objects, such as foundations, further away from the vehicle than has heretofore been possible with apparatus which is simple, reliable and compact.

The invention features an improved construction of a backhoe which has a supporting member arranged to be attached to a vehicle, a boom having a longitudinal axis and being pivotally connected at one end to the supporting member and arranged to be rotated at that end about a first horizontal axis and swung at that end about a vertical axis, a dipper stick pivotally connected to the boom, arranged to be rotated with respect to the boom about a second horizontal axis and further arranged to have connected thereto, at the end remote from the second horizontal axis and the boom, elements, respectively, for excavating and lifting, the dipper stick also having means for rotating a connected element, a doubleacting hydraulic boom cylinder with one end connected to the supporting member and the other end connected to the boom and being arranged to rotate the boom about the first horizontal axis and a double-acting hydraulic crowd cylinder having one end connected to the dipper stick and being arranged to rotate the dipper stick about the second horizontal axis. In the improved construction the boom and the dipper stick are pivotally connected to each other at their adjacent ends and the backhoe includes a mechanism connected to both the boom and the dipper stick for rotating the dipper stick about the second horizontal axis on either side of the longitudinal axis of the boom.

In preferred embodiments the mechanism includes a second double-acting hydraulic cylinder pivotally connected at one end to either the boom or the dipper stick; the mechanism includes the crowd cylinder and a portion of the mechanism is connected to the other end of the crowd cylinder; the mechanism includes an auxiliary double-acting hydraulic cylinder pivotally connected at one end to the boom; the mechanism also has a link pivotally connected to the crowd cylinder and to the other end of the auxiliary double-acting hydraulic cylinder and the link is pivotally connected to at least one of the boom and the dipper stick; the link is pivotally connected to both the boom and the dipper stick at the pivotal connection at their adjacent ends; the crowd cylinder and the auxiliary double-acting hydraulic cylinder are connected to the top surfaces of the dipper stick and the boom respectively, the link is at least partially disposed above the boom and the dipper stick, and the boom is arranged to be rotated about the first horizontal axis into an upright position and the dipper stick is arranged to be rotated about the second horizontal axis into a position extending lengthwise above the vehicle when the crowd cylinder and the auxiliary cylinder are actuated into their respective fully closed positions; and the backhoe also includes a mechanism for swinging the boom at least 180 about a vertical axis;

Other objects, features and advantages will become apparent from the following description of a preferred embodiment of the invention, taken together with the attached drawings thereof, in which:

FIG. 1 is a side elevation of a backhoe assembly constructed in accordance with the invention, supported on a vehicle for stability and for transport and having the dipper stick positioned above the vehicle roof;

FIG. 2 is a diagrammatic top elevation of the vehicle and backhoe illustrating the full 360 dipper stick horizontal swing provided by the invention;

FIG. 3 is a diagrammatic side elevation of a backhoe and vehicle illustrating the range of dipper stick rotation provided by the invention;

FIG. 4 is a side elevation illustrating the conventional excavating configuration for the boom and dipper stick of the backhoe assembly;

FIG. 5 is a side elevation illustrating the low force lifting configuration for the dipper stick; and

FIG. 6 is a side elevation illustrating a configuration of the boom and dipper stick useful for excavating beneath objects, such as sidewalks, foundations, and pipes.

With reference to FIG. 1, there is shown a vehicle 10 to the rear of which is mounted a frame member 12 supported on vehicle 10 by any suitable means and carrying conventional stabilizers 14 (shown in their down or stabilizing position) on each side thereof. Stabilizers 14 are actuated by double-acting hydraulic cylinders 15. A swing frame 16 is journaled on swing pin 18 and arranged to be rotated about a vertical axis 20 on frame member 12. Although any conventional mechanism for swinging swing frame 16 may be employed, in the described embodiment it is preferred-and in order to achieve all of the advantages of the invention hereinafter described, it is necessary-that the mechanism employed permit a wide range of swing. Thus, in the preferred embodiment the invention employs the Boom Swing System described in my US. Pat. No. 3,395,812, issued on Aug. 6, 1968, which provides a 185 range of swing for a swing frame and boom and the structural details of which are hereby incorporated by reference.

Returning now to a description of the preferred embodiment shown in FIGS. 1 through 6, a boom 22 is pivotally mounted at end 26 on swing frame 16 by pin 24 and is arranged to be rotated about a horizontal axis through pin 24 by a double-acting hydraulic cylinder 28 (the boom cylinder") having its cylinder end 30 pivotally secured to swing frame 16 by pin 32 and its piston end 34 pivotally secured by pin 36 to a raised portion 38 of boom 22 at a point intermediate its ends 26 and 40. A standard dipper stick 42 is pivotally secured at end 44 to end 40 of boom 22 by a hinge pin 46 and has at its other end 48 a hinge pin 50 arranged to rotatably support any of a plurality of lifting and excavating attachments. In FIG. 1 a lifting jib 52 is secured upon pin 50 and a link 54 and link member 56 are pivotally secured to dipper stick 42 and lifting jib 52 by hinge pins 58 and 60 respectively and to each other by hinge pin 62. Dipper stick 42 is provided with a double-acting (bucket) cylinder 63 which has its piston end 64 pivotally secured to hinge pin 62 and its cylinder end 66 pivotally secured to dipper stick 42 by pin 68 and is arranged to rotate jib 52 about a horizontal axis through pin 50.

A substantially triangular common link 70 is pivotally secured near one corner 72 on pin 46. An auxiliary doubleacting hydraulic cylinder (link positioning cylinder) 74 has cylinder end 76 pivotally secured to a second raised portion 77 of boom 22 by pin 78 and its piston end 80 pivotally secured to comer 82 of common link 70 by pin 84 and is arranged to rotate link 70 about pin 46. A double-acting hydraulic (crowd) cylinder 86 has piston end 88 pivotally secured to dipper stick 42 by pin 90 and cylinder end 92 pivotally secured to comer 94 of common link 70 by pin 96. Each of boom cylinder 28, link positioning cylinder 74, bucket cylinder 63 and crowd cylinder 86 is arranged to be actuated independently by hydraulic fluid controlled by conventional control valving (not shown) and moved between a fully closed position, in which their respective piston rods are disposed substantially within their respective cylinders and a fully open position in which their respective piston rods are disposed substantially external to their respective cylinders and in which the respective double-acting cylinders are substantially longer than in the fully closed position.

As is apparent from the drawings, boom cylinder 28 is arranged to rotate boom 22 about pin 24 independently of the actuation of the other cylinders, bucket cylinder 63 is arranged to cooperate with link 54, link member 56, and hinge pins 58, 60 and 62 and to rotate lifting jib 52 about pin 50 independently of the actuation of the other three cylinders, common link 70 is arranged to be rotated about pin 46 only by actuation of link positioning cylinder 74, and dipper stick 42 is arranged to be rotated about pin 46 by actuation of either link positioning cylinder 74, crowd cylinder 86 or of both.

Referring now to FIG. 4 (in which the lifting jib 52 of FIG. 1 has been replaced by scoop 98), in operation when link positioning cylinder 74 and crowd cylinder 86 are actuated substantially into their fully open positions, dipper stick 42 is rotated about pin 46 until dipper stick 42 is disposed substantially below the longitudinal axis 100 of boom 22. When the backhoe has assumed the position shown, excavation may be performed in the customary manner by appropriate actuation of bucket cylinder 63 and boom cylinder 28.

One of the advantages of the backhoe constructed in accordance with the invention is illustrated in FIG. 5. In this figure boom cylinder 28 has been opened until boom 22 rotates downwardly around pin 24 until end 40 rests on the ground. Appropriate actuation of link positioning cylinder '74, crowd cylinder 86 and/or bucket cylinder 63 may then be employed to lift heavy objects, either by means of a chain suspended from a pin 102 on scoop 98 or from a lifting jib 52. Thus, the lifting is performed about a fulcrum point, designated 104, near end 40 of boom 22, rather than at stabilizers 14 and hydraulic stabilizer cylinders 15, permitting lifting of objects of identical weight using substantially less force than is required with a conventional backhoe lifting from a configuration similar to that shown in FIG. 4 and at the same time permitting the lifting of heavier objects than would be possible with a conventional backhoe without lifting the front wheels of vehicle off the ground. Furthermore, since boom 22 rests on the ground, leakage in boom cylinder 28 does not occur during the lifting operation and leakage in crowd cylinder 86 is offset by leakage in stabilizer cylinders 15.

As is illustrated in FIG. 6, when boom cylinder 28 is fully extended, bucket cylinder 63 substantially closed and link positioning cylinder 74 and crowd cylinder 86 appropriately positioned, scoop 98 is positioned to excavate beneath a sidewalk 106 or similar structure, for example, a foundation. Conventional backhoes, which have a restricted digging configuration, similar to that shown in FIG. 4, cannot dig under such objects, nor can they excavate as far away from the vehicle 10 as can a backhoe constructed in accordance with the invention. Furthermore, for a wide range of excavating depths in both the excavating configuration of FIG. 6 and that of FIG. 4, appropriate actuation of link positioning cylinder 74 and crowd cylinder 86 permits alignment of the longitudinal axis 108 of link 70 perpendicular to the longitudinal axis 109 of crowd cylinder 86, thereby maximizing the crowd moment and the digging force at the teeth of scoop 98 produced by further actuation of crowd cylinder 86.

FIGS. 2 and 3 illustrate the effective range of operation of the invention incorporating the boom swing system referred to above. When the boom 22 and dipper stick 42 are in the positions shown in FIGS. 4, 5, and 6 they may be swung about vertical axis on swing frame 16 over a range of l85 (designated by the arrows l 10) in a region generally rearward of stabilizers l4 and, as is best shown in FIG. 3, the range of continuous vertical rotation of scoop 98, dipper stick 42, and boom 22 about pin 24 with respect to vehicle 10 is approximately 270. In the fully raised position shown in FIG. 1, in which boom cylinder 28, link positioning cylinder 74 and crowd cylinder 86 are fully closed, boom 22 is in an upright position (substantially vertical in the preferred embodiment) and dipper stick 42 extends lengthwise above the top of vehicle 10. With link positioning cylinder 74 and crowd cylinder 86 fully closed, the swing system may be actuated and boom 42 and lifting jib 52 rotated through a full 185 (designated by arrows 112 in FIG. 2) and the vehicle 10 and the backhoe may be effectively employed to carry an object on either side of vehicle 10 or forwardly thereof and may be employed to lift objects from one side of vehicle 10 over the vehicle to the other side. The mass of boom 22, boom cylinder 28 and link positioning cylinder '74 counterbalance the object as it is swung permitting more accurate positioning and stopping of the object. When the backhoe assembly carries a load in the position shown in FIG. 1, the center of gravity for transport thereof is moved substantially forward of the rear axle of the vehicle 10, greatly improving stability of the vehicle over the conventional manner of transport in which the load is carried to the rear of the swing mechanism and the center of gravity of transport is to the rear of vehicle 10. Thus, a backhoe constructed in accordance with the invention may be employed to carry heavier loads than a backhoe having the conventional rear-carried load configuration. Since boom cylinder 28, link positioning cylinder 74, and crowd cylinder 86 are in their respective fully closed positions, hydraulic valve and cylinder leakage, which conventionally occurs with a rearcarried load and permits the assembly to gradually fall downward, does not occur. Finally, a backhoe assembly which permits the configuration shown in FIG. 1, provides a substantially shorter transport height and transport length than is possible with conventional backhoe assemblies.

What is claimed is:

1. In a backhoe comprising a supporting member arranged to be attached to a vehicle, a boom having a longitudinal axis and being pivotally connected at one end to said supporting member and arranged to be rotated at said end about a first horizontal axis and swung at said end around a vertical axis, a dipper stick pivotally connected to said boom, arranged to be rotated with respect to said boom about a second horizontal axis and further arranged to have connected thereto, at the end remote from said second horizontal axis and said boom, elements, respectively for excavating and lifting, said dipper stick having means for rotating a connected said element, a double-acting hydraulic boom cylinder having one end con nected to said supporting member and the other end connected to said boom and arranged to rotate said boom about said first horizontal axis, and a double-acting hydraulic crowd cylinder having one end connected to said dipper stick and being arranged to rotate said dipper stick about said second horizontal axis,

the improvement wherein:

said boom and said dipper stick are pivotally connected to each other at their adjacent ends; and,

said backhoe comprises a mechanism connected to both said boom and said dipper stick for rotating said dipper stick about said second horizontal axis on either side of said longitudinal axis of said boom,

said mechanism including said crowd cylinder, an auxiliary doubleacting hydraulic cylinder, and a link,

one end of said auxiliary hydraulic cylinder being pivotally connected to said boom and the other end of said auxiliary hydraulic cylinder being pivotally connected to said link,

the other end of said crowd cylinder being pivotally connected to said link, and,

said link also being pivotally connected to at least one of said boom and said dipper stick.

2. The backhoe of claim 1 wherein said link is pivotally connected to both said boom and said dipper stick at the pivotal connection at their said adjacent ends.

3. The backhoe of claim 2 wherein said crowd cylinder and said auxiliary double-acting hydraulic cylinder are connected to the top surfaces of said dipper stick and said boom respectively and said link is at least partially disposed above said boom and said dipper stick, said boom being arranged to be rotated about said first horizontal axis into an upright position and said dipper stick being arranged to be rotated about said second horizontal axis into a position extending length-wise above said vehicle when said crowd cylinder and said auxiliary cylinder are actuated into their respective fully closed positrons.

4. The backhoe of claim 3 further including a mechanism for swinging said boom about a vertical axis.

5. The backhoe of claim 3 further including a mechanism for swinging said boom at least 180 degrees about a vertical axis.

6. In a backhoe comprising a supporting member arranged to be attached to a vehicle, a boom having a longitudinal axis and being pivotally connected at one end to said supporting member and arranged to be rotated at said end about a first horizontal axis and swung at said end around a vertical axis, a dipper stick pivotally connected to said boom, arranged to be rotated with respect to said boom about a second horizontal axis and further arranged to have connected thereto, at the end remote from said second horizontal axis and said boom, elements, respectively for excavating and lifting, said dipper stick having means for rotating a connected said element, a double-acting hydraulic boom cylinder having one end connected to said supporting member and the other end connected to said boom and arranged to rotate said boom about said first horizontal axis, and a double-acting hydraulic crowd cylinder having one end connected to said dipper stick and being arranged to rotate said dipper stick about said second horizontal axis,

the improvement wherein said boom and said dipper stick are pivotally connected to each other at their adjacent ends and said backhoe includes a first mechanism connected to both said boom and said dipper stick for rotating said dipper stick about said second horizontal axis on either side of said horizontal axis of said boom, and a second mechanism for swinging said boom at least about a vertical axis.

7. The backhoe of claim 6 wherein said second mechanism includes an auxiliary double-acting hydraulic cylinder pivotally connected at one end to said boom, said crowd cylinder and said auxiliary double-acting hydraulic cylinder being connected to the top surfaces of said dipper stick and said boom respectively, said boom being arranged to be rotated about said first horizontal axis into an upright position and said dipper stick being arranged to be rotated about said second horizontal axis into a position extending lengthwise above said vehicle when said crowd cylinder and said auxiliary cylinder are actuated into their respective fully closed positlons. 

1. In a backhoe comprising a supporting member arranged to be attached to a vehicle, a boom having a longitudinal axis and being pivotally connected at one end to said supporting member and arranged to be rotated at said end about a first horizontal axis and swung at said end around a vertical axis, a dipper stick pivotally connected to said boom, arranged to be rotated with respect to said boom about a second horizontal axis and further arranged to have coNnected thereto, at the end remote from said second horizontal axis and said boom, elements, respectively for excavating and lifting, said dipper stick having means for rotating a connected said element, a double-acting hydraulic boom cylinder having one end connected to said supporting member and the other end connected to said boom and arranged to rotate said boom about said first horizontal axis, and a double-acting hydraulic crowd cylinder having one end connected to said dipper stick and being arranged to rotate said dipper stick about said second horizontal axis, the improvement wherein: said boom and said dipper stick are pivotally connected to each other at their adjacent ends; and, said backhoe comprises a mechanism connected to both said boom and said dipper stick for rotating said dipper stick about said second horizontal axis on either side of said longitudinal axis of said boom, said mechanism including said crowd cylinder, an auxiliary double-acting hydraulic cylinder, and a link, one end of said auxiliary hydraulic cylinder being pivotally connected to said boom and the other end of said auxiliary hydraulic cylinder being pivotally connected to said link, the other end of said crowd cylinder being pivotally connected to said link, and, said link also being pivotally connected to at least one of said boom and said dipper stick.
 2. The backhoe of claim 1 wherein said link is pivotally connected to both said boom and said dipper stick at the pivotal connection at their said adjacent ends.
 3. The backhoe of claim 2 wherein said crowd cylinder and said auxiliary double-acting hydraulic cylinder are connected to the top surfaces of said dipper stick and said boom respectively and said link is at least partially disposed above said boom and said dipper stick, said boom being arranged to be rotated about said first horizontal axis into an upright position and said dipper stick being arranged to be rotated about said second horizontal axis into a position extending length-wise above said vehicle when said crowd cylinder and said auxiliary cylinder are actuated into their respective fully closed positions.
 4. The backhoe of claim 3 further including a mechanism for swinging said boom about a vertical axis.
 5. The backhoe of claim 3 further including a mechanism for swinging said boom at least 180 degrees about a vertical axis.
 6. In a backhoe comprising a supporting member arranged to be attached to a vehicle, a boom having a longitudinal axis and being pivotally connected at one end to said supporting member and arranged to be rotated at said end about a first horizontal axis and swung at said end around a vertical axis, a dipper stick pivotally connected to said boom, arranged to be rotated with respect to said boom about a second horizontal axis and further arranged to have connected thereto, at the end remote from said second horizontal axis and said boom, elements, respectively for excavating and lifting, said dipper stick having means for rotating a connected said element, a double-acting hydraulic boom cylinder having one end connected to said supporting member and the other end connected to said boom and arranged to rotate said boom about said first horizontal axis, and a double-acting hydraulic crowd cylinder having one end connected to said dipper stick and being arranged to rotate said dipper stick about said second horizontal axis, the improvement wherein said boom and said dipper stick are pivotally connected to each other at their adjacent ends and said backhoe includes a first mechanism connected to both said boom and said dipper stick for rotating said dipper stick about said second horizontal axis on either side of said horizontal axis of said boom, and a second mechanism for swinging said boom at least 180* about a vertical axis.
 7. The backhoe of claim 6 wherein said second mechanism includes an auxiliary double-acting hydraulic cylinder pivotally connected at onE end to said boom, said crowd cylinder and said auxiliary double-acting hydraulic cylinder being connected to the top surfaces of said dipper stick and said boom respectively, said boom being arranged to be rotated about said first horizontal axis into an upright position and said dipper stick being arranged to be rotated about said second horizontal axis into a position extending lengthwise above said vehicle when said crowd cylinder and said auxiliary cylinder are actuated into their respective fully closed positions. 